Fixation and Inactivation of Staphylococcal Leukocidin by Phosphatidylcholine and Ganglioside G M1 in Rabbit Polymorphonuclear Leukocytes

1980 ◽  
Vol 29 (2) ◽  
pp. 678-684
Author(s):  
Masatoshi Noda ◽  
Iwao Kato ◽  
Toshiya Hirayama ◽  
Futami Matsuda
Keyword(s):  
Cholera Toxin ◽  
Carboxymethyl Cellulose ◽  
Polymorphonuclear Leukocytes ◽  
Receptor Site ◽  
Maximal Effect ◽  
Diffusion Technique ◽  
Subunit B ◽  
Gel Diffusion

Staphylococcal leukocidin is resolved by chromatography on carboxymethyl cellulose columns into two components, which are designated F (fast) and S (slow). Fixation and inactivation of both components were studied as follows. (i) Leukocidin activity was confined to the first 10 min of intoxication, and the maximal effect resulted from treating 10 6 rabbit peripheral polymorphonuclear leukocytes per 20 μl with 0.5 ng of each component of leukocidin. The S component was more responsible for the interaction with the leukocytes than the F component. (ii) The F component was inactivated by phosphatidylcholine at concentrations which corresponded to molar proportions of 1:1 and bound to [ 14 C]phosphatidylcholine at equimolar proportions. (iii) The S component was inactivated by ganglioside G M1 at 1:1 molar proportions, but not by any of the related glycolipids. Ganglioside G M1 also was precipitated with the S component by a gel diffusion technique. Subunit B of cholera toxin competitively inhibited the binding of the S component to rabbit leukocyte membranes. This indicates that ganglioside G M1 may resemble or be part of the receptor site for the S component.

scholarly journals Activation by cholera toxin of adenylate cyclase solubilized from rat liver

1976 ◽  
Vol 157 (3) ◽  
pp. 785-787 ◽  
Author(s):  
S Van Heyningen
Keyword(s):  
Adenylate Cyclase ◽  
Cholera Toxin ◽  
Rat Liver ◽  
Thiol Group ◽  
Subunit B

Cholera toxin, or peptide A1 from the toxin, activates adenylate cyclase solubilized from rat liver with Lubrol PX, provided that cell sap, NAD+, ATP and thiol-group-containing compounds are present. The activation is abolished by antisera to whole toxin, but not to subunit B.

PLATELET-DEPENDENT ACTIVATION AND AMPLIFICATION OF THE POLYMORPHONUCLEAR LEUKOCYTES LYSOSOMAL ENZYME RELEASE

1987 ◽  
Author(s):  
A Del Maschio ◽  
E Corvazier ◽  
F Maillet ◽  
M Kazatchkine ◽  
J Maclouf
Keyword(s):  
Lysosomal Enzyme ◽  
Polymorphonuclear Leukocytes ◽  
Maximal Effect ◽  
Enzyme Release ◽  
Maximal Intensity ◽  
Platelet Concentration ◽  
Human Pmns ◽  
Stimulation Of

The degranulatlon of human PMNs by opsonlsed zymosan (OpZ) was studied In the presence or In the absence of platelet alone or after stimulation by thrombin. Evidence Is presented that the presence of platelets Increased the extent of the liberation of lysozyme from PMNs stimulated by OpZ with a maximal intensity when they were stimulated by thrombin. The extent of the amplification was higher when the PMNs trigger was lower (i.e. 0.5 x 108 particles/ml as compared to 3.0 x 108 particles). This effect was dependent on the platelet concentration (from 10-80 platelets/PMN). Platelets stimulated by thrombin could alsoactivate the resting PMNs with a maximum obtained ata thrombin concentration of 0.1 U/ml, corresponding to the maximal release by these cells of products stored In their granules. However, the substitution ofplatelet suspensions by the released products found In their supernatant after stimulation by thrombin, resulted In a comparable stimulation only at platelet concentrations above the ones for coincubation experiments. These findings suggest that the presence of platelets themselves or In combination with their released products are responsible for this amplification. The use of zymosan alone or coated with IgG, C3b1, C3b or OpZ did not reveal any specificity of the Inducer for this amplification suggesting that platelets and/or platelet products acted by enhancing acommon step of PMNs activation Independent of the stimulus carried by the particles. Additionally, It could be noted that the maximal effect of the amplification by platelets occurred when the level of stimulation of the PMNs alone was the weakest.

scholarly journals Endocytosis of cholera toxin in GERL-like structures of murine neuroblastoma cells pretreated with GM1 ganglioside. Cholera toxin internalization into Neuroblastoma GERL.

1979 ◽  
Vol 81 (3) ◽  
pp. 543-554 ◽  
Author(s):  
K C Joseph ◽  
A Stieber ◽  
N K Gonatas
Keyword(s):  
Golgi Apparatus ◽  
Horseradish Peroxidase ◽  
Cholera Toxin ◽  
Plasma Membranes ◽  
Neuroblastoma Cells ◽  
Gm1 Ganglioside ◽  
Murine Neuroblastoma ◽  
Positive Elements ◽  
Subunit B ◽  
Cytochemical Marker

Cholera toxin (CT), covalently attached to horseradish peroxidase (HRP), is a specific cytochemical marker for GM1 ganglioside (GM1) and retains the ability of the native toxin to raise levels of cyclic AMP in avian erythrocytes. Using a cytochemical stain for HRP, we found that 9% of control cultured murine neuroblastoma cells bound cholera toxin-horseradish peroxidase conjugates (CT-HRP) on their surfaces after incubations for 1 h at 4 degrees C. Exogenous GM1, the natural receptor of CT, becomes associated in the culture medium with the plasma membranes of these cells so that 96% of cells are stained. Cells preincubated with GM1 at 4 degrees C were exposed to CT-HRP for 1 h at 4 degrees C. After washing, cells were incubated at 37 degrees C for 30 min-24 h. Endocytosis of CT-HRP occurred within 30 min and CT-HRP remained, throughout the 24-h period, in tubules, vesicles, and cisternae often found near the Golgi apparatus; this aggregate of peroxidase-positive elements probably corresponds to Golgi apparatus-endoplasmic reticulum-lysosomes (GERL) of neurons. In metaphase cells, CT-HRP was observed in aggregates of vesicles and tubules clustered near the centriole. Conjugates of HRP with subunit B, the GM1 binding component of CT, were internalized by cells pretreated with GM1 as was CT-HRP. The 9% of neuroblastoma cells binding CT-HRP in the absence of exogenous GM1 internalized the ligand in a manner indistinguishable from that of the treated cells. These findings indicate that, in neuroblastoma cells, a system of vesicles, tubules, and cisternae, analogous to GERL of neurons, is the primary recipient of adsorptive endocytosis of CT bound to endogenous or exogenously introduced GM1.

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